(LE1) Chemistry Flashcards
What does the top number represent?
Atomic number: number of protons
What does the bottom number represent?
Atomic mass: number of protons + number of neutrons
What is an isotope?
Same element with different atomic mass. Different number of neutrons
What are valence electrons?
electrons in the outer shell
How many electrons are in an uncharged atom?
The amount is equal to the number of protons
How is charge determined?
by an unequal number of electrons to protons
What are ionic bonds?
donate/accept electrons
- strong bonds
What are covalent bonds?
share pairs of electrons
- strongest type of bond
What is a Hydrogen bond?
Uneven sharing of electrons results in partial negative in one molecule attracted to partial positive in another molecule
- very weak bond. Electrons aren’t donated/accepted or shared
ex/ H2O molecules
What do acids dissociate into? Name an example
Dissociates into H+ and anions
Ex/ HCl -> H+ Cl-
What do bases dissociate into? Name an example
Dissociates into OH- (hydroxide) and cations
Ex/ NaOH -> Na+ OH-
What do salts dissociate into? Name an example
Cation and anion together. Does not dissociate into H+ or OH-
Ex/ NaCl -> Na+ Cl-
What is the relation of the pH scale to [H+]
Inversely proportional to H+ content
Each value is 10x different
Ex/ pH 7 is 100x less acidic than pH 5
What are buffers?
prevent large pH fluctuations
ex/ PBS - phosphate buffered saline
Name this functional group
Hydroxyl group
Name this functional group
Carbonyl group
Name this functional group
Carboxyl group
Name this functional group
Amino group
Name this functional group
Phosphate group
Explain what is occurring in this image. What is the specific name? What kind of bond is formed?
Dehydration synthesis to join monomers to make a polymer
- releases a water molecule in the process
This image is specifically Glycosidic linkage
- Glucose + Glucose = Maltose
Covalent bond
Explain what is occurring in this image
Hydrolysis to break polymers into monomers
- requires a water molecule in the process
Draw an amino acid molecule